#!/usr/bin/env bash
set -euo pipefail

# --- SUDO CHECK ---
if [ "$EUID" -ne 0 ]; then
    echo "This script requires root privileges. Re-running with sudo..."
    exec sudo "$0" "$@"
fi

# --- HANDLE -k OPTION FOR KEY FILE ---
BORG_PASSPHRASE=""

while getopts "k:" opt; do
    case "$opt" in
        k)
            BORG_PASSPHRASE=$(<"$OPTARG")
            if [ -z "$BORG_PASSPHRASE" ]; then
                echo "Error: The key file is empty."
                exit 1
            fi
            echo "Using passphrase from key file: $OPTARG"
            ;;
        *)
            echo "Usage: $0 [-k passphrase_file] <repo>"
            exit 1
            ;;
    esac
done
shift $((OPTIND - 1))

# --- FALLBACK TO /run/secrets/borg_passwd IF NO KEY FILE ---
if [ -z "$BORG_PASSPHRASE" ]; then
    if [ -f "/run/secrets/borg_passwd" ]; then
        BORG_PASSPHRASE=$(<"/run/secrets/borg_passwd")
        echo "Using passphrase from /run/secrets/borg_passwd"
    else
        # Prompt user for passphrase if neither -k nor /run/secrets/borg_passwd is available
        read -s -p "Enter Borg repository passphrase: " BORG_PASSPHRASE
        echo
    fi
fi

export BORG_PASSPHRASE

# --- DEFAULT REPO ---
REPO="${1:-/holocron/backups}"

# --- CHECK REQUIRED COMMANDS ---
for cmd in borg fzf find tree cp mkdir; do
    command -v "$cmd" >/dev/null || { echo "Error: '$cmd' is required but not installed."; exit 1; }
done

# --- LIST ARCHIVES (sorted, newest last) ---
mapfile -t archives < <(borg list --format="{archive}{NL}" "$REPO" | sort)
if [ ${#archives[@]} -eq 0 ]; then
    echo "No archives found in $REPO"
    exit 1
fi

# --- FZF ARCHIVE SELECT ---
selected=$(printf '%s\n' "${archives[@]}" | fzf --prompt="Select archive: " --height=40% --border --reverse)
if [ -z "$selected" ]; then
    echo "No archive selected."
    exit 1
fi
echo "Selected archive: $selected"

# --- GENERATE A UNIQUE, SHORTER MOUNT POINT ---
MOUNT_POINT="/tmp/borg-mount-${selected}-$(uuidgen | sha256sum | head -c 6)"
mkdir -p "$MOUNT_POINT"

# --- MOUNT ARCHIVE ---
echo "Mounting '$selected' to $MOUNT_POINT..."
borg mount "$REPO::$selected" "$MOUNT_POINT"

if [ ! -d "$MOUNT_POINT" ]; then
    echo "Error: mount failed."
    exit 1
fi

# --- LIST FILES AND DIRECTORIES ---
echo "Scanning files and directories..."
if command -v fd >/dev/null 2>&1; then
    # List files and directories using fd (can handle both files and dirs)
    files=$(fd --type f --type d . "$MOUNT_POINT" | sort)
else
    # Fall back to find if fd is not available
    files=$(find "$MOUNT_POINT" -type f -o -type d | sort)
fi

if [ -z "$files" ]; then
    echo "No files or directories found in archive."
    borg umount "$MOUNT_POINT"
    rm -rf "$MOUNT_POINT"
    exit 1
fi

# --- HIERARCHICAL FZF FILE/DIRECTORY SELECTION (REVERSED) ---
# We reverse the order of files to display the latest (newest) files/folders at the top.
selected_files=$(printf '%s\n' "$files" | sed "s|$MOUNT_POINT/||" | tac | fzf \
    --multi \
    --height=50% \
    --border \
    --prompt="Select files or directories to restore: " \
    --preview "tree -C -L 5 $MOUNT_POINT/$(dirname {})" \
    --preview-window=right:50% \
    --delimiter='/' \
    --with-nth=1..)

if [ -z "$selected_files" ]; then
    echo "No files or directories selected. Exiting."
    borg umount "$MOUNT_POINT"
    rm -rf "$MOUNT_POINT"
    exit 0
fi

# --- SUMMARY OF SELECTED FILES/DIRECTORIES ---
echo "Selected files and directories:"
for file in $selected_files; do
    echo "  $file"
done

# --- OPTIONS MENU (concise) ---
# Default to option 1 if no input is given
echo "Select restore destination: 1) Restore to ./${selected}_restore  2) Restore to original dirs  3) Quit"
read -p "Enter your choice (1/2/3) [default: 1]: " choice
# Default to option 1 if user presses Enter without providing input
choice="${choice:-1}"

# --- SET RESTORE DESTINATION BASED ON USER CHOICE ---
case "$choice" in
    1)
        DEST="./${selected}_restore"
        ;;
    2)
        DEST="$MOUNT_POINT"
        ;;
    3)
        echo "Quitting. No files restored."
        borg umount "$MOUNT_POINT"
        rm -rf "$MOUNT_POINT"
        exit 0
        ;;
    *)
        echo "Invalid choice. Exiting."
        borg umount "$MOUNT_POINT"
        rm -rf "$MOUNT_POINT"
        exit 1
        ;;
esac

mkdir -p "$DEST"

# --- RESTORE FILES AND DIRECTORIES ---
echo "Restoring selected files and directories..."
while IFS= read -r file; do
    # Path is already stripped of /tmp, so no need for further modification
    dest_path="$DEST/$file"
    mkdir -p "$(dirname "$dest_path")"
    # If it's a directory, we use cp -r to ensure the directory structure is restored
    if [ -d "$MOUNT_POINT/$file" ]; then
        cp -r "$MOUNT_POINT/$file" "$dest_path"
    else
        cp -a "$MOUNT_POINT/$file" "$dest_path"
    fi
    echo "Restored: $file"
done <<< "$selected_files"

# --- CLEANUP ---
borg umount "$MOUNT_POINT"
rm -rf "$MOUNT_POINT"
echo "Restore complete."